Known For: Its heat! This style, introduced by former gold-medal Olympic weight lifter and Indian yoga guru Bikram Choudhury, is practiced in a heated room (around 105 degrees Fahrenheit) with a humidity level of 40 percent. “The idea is that the heat helps promote flexibility, strength, endurance, weight loss and detoxification,” explains Kaloudis.
Best Suits: Those who like repetition, consistency, intensity and heat. Anyone with pre-existing health conditions should avoid Bikram, or check with their doctor first. Even then, proceed with caution.
What It's Like: Sweaty! A 90-minute class consists of 26 postures, repeated twice without variation. While devotees swear that the heat helps with everything from detoxification to preventing injury, health experts aren’t so sure. “Sweating doesn’t release toxins,” says Michele Olson, Ph.D., professor of exercise science at Auburn University in Aurburn, AL. "And, there is no study that has tested the theory that a heated room improves flexibility." We have better flexibility whenever our muscles and tendons experience greater blood flow and, Olson suggests, we can easily achieve that with a proper warm up.